Automatic power transmitting mechanism



Aug. 17, 1937. J. E. PADGETT AUTOMATIC POWER TRANSMITTING MECHAISM FiledJune 19, 1933 Patented lAug. 17, 1937 UNITED STATES PATENT OFFICEAUTOMATIC POWER TRANSMITTING MECHANISM Jersey Application June 19, 1933,Serial No. 676,567

14 Claims.

The present invention relates to mechanisms for automaticallytransmitting power from a driving shaft to a driven shaft when therespective speeds of the shafts are properly correlated for eiicientoperation.

More particularly, the present invention relates to automatic clutchmechanisms, and although they possess operating characteristics andstructural features that render them especially useful in automotive orlike drives, they may be employed in a Wide variety of powertransmitting drives. 'I'he present invention also possesses manyfeatures that may be advantageously employed in manually operable clutchmechanisms and therefore the following description and claims areintended to embrace manual as Well as automatic clutch mechanisms.

The present invention further has to do with novel methods and apparatusfor statically and dynamically balancing clutch mechanisms, moreparticularly clutch mechanisms of the self operating or automatic type.

The present application is a continuation-inpart of my cdpending.application Serial No.

669,766, filed May 6, 1932, which may be referred to for a more detaileddisclosure of the automatic clutch mechanism to which my invention isapplied.

In most all automatic clutch mechanisms herey tofore proposed the. speedresponsive mechanism takes the form of a centrifugally operable deviceand as the latter is usually of comparatively large mass, it has beennecessary to accurately design the parts, both for dimensional accuracyand mass l distribution, in order to prevent the mechanism from becomingunbalanced in operation. It has been found, however, that producingclutch mechanisms in this manner has not only made them so costly ofmanufacture as to seriously militate against their commercial adoptionbut it often has resulted in production of mechanisms which, for somereason or other, are either statically or dynamically unbalanced orboth.

Automatic clutch mechanisms heretofore prov.45 posed are also open tothe objection that they embody plate, or plate and weight organizationsof considerable mass which must move freely axially of the mechanismduring operation, and in order to provide such movement driving key or'50 lugorganizations have been employed which have considerable play orlost motion, with the result that the plate, or plate and Weightassemblies are allowed to shift radially or sidewise of the mechanism.Radial, or sidewise shifting of the plate '55 or plate and Weightassemblies has caused these and then operating upon the assembledmechaprior mechanisms to be statically and dynamically unbalanced withthe result that even when operating at moderately high speeds, theyvibrate to an undesirable extent.

It is a primary object of the present invention 5 to devise automaticclutch mechanisms which are statically aswell as dynamically balanced atall times and whose operation is free from vibration.

It is a further major object of lmy invention to l0 devise clutchmechanisms which are durable, eicient and statically and dynamicallybalanced during all phases of their operation; and yetwhich may bemanufactured by low-cost. quantity production methods. 15

My invention further aims to devise a novel method of balancing clutchmechanisms which consists of manufacturing clutch mechanisms withoutregard to the precise dimensioning of the parts so as to provide dynamicor static balance, 20

nisms to establish dynamic as Well as static balance thereof.

It is a further important object of the present invention to devise foruse in clutch mechanisms 25 of the type wherein parts thereof aremounted for free axial movement, and which have suiicient lost motion orplay to allow them to shift radially; novel mechanism for establishingand maintaining accurate balance of the mechanisms at all 30 times,whereby smoothly operating clutch mechanisms are produced.

Another object of my invention is to devise a novel method ofestablishing and maintaining accurate dynamic and static balance ofclutch mech- 35 anisms of the type having axially movable members whichare provided with play or lost motion permitting them to move sidewise,which comprises taking up the lost motion and balancing the mechanism,and then providing the mecha- 40 nism parts with means for yieldinglyholding them in balanced condition during all'phases of their operation.

Another object of my invention is to devise a novel method of balancingclutch mechanisms of 45 In the drawing: Figure 1 is a longitudinal viewof the automatic clutch mechanism forming part of my invention. Figure 2is a view of the clutch mechanism shown in Figure 1 as it appears whenviewed from the right hand side of that figure with the throwoutmechanism removed and parts in section to more clearly illustrate thestructure involved.

Figure 3 is a fragmental sectional view of the clutch mechanism shown inFigure 1 and illustrates the manner of mounting the holdback and drivingpressure springs in the mechanism; and

Figure 4 is a fragmental sectional view of the mechanism shown in Figure1 and illustrates one of the automatic weights disposed in its outermostposition, and the plates automatically engaged.

Referring to the drawing, wherein like reference characters refer tolike parts throughout the several Views thereof, my automatic clutchmechanism is preferably enclosed in a clutch housing that is illustratedas broken away for the most part, and it is designated by the referencecharacter I.

A driving shaft 3 is adapted to have rotational efforts applied to it bya suitable prime mover in any desired manner, and in the presentinstance, it is shown as constituting the crank shaft of an internalcombustion engine. The end of the shaft 3 is secured to a flywheel 4 bybolts 5, or in any other suitable manner. Bolts 5 extend through alignedapertures in the flywheel and the flange provided .on the end of shaft3, and have nuts turned thereon.

Shaft 3 is further provided with a bore 6 in which is carried a bearingassembly 1 for supporting the reduced end 9 of a clutch shaft 9. Therear end of shaft 9 is adapted to be jour` naled in a bearing assembly(not shown) that is preferably located in recess III in housing I.

A hub II is splined upon shaft 9 and is provided with a flange I2.operatively secured to flange I2, by means of rivets or the like, is avibration dampener designated generally by reference character I3 whichprovides a resilient driving connection between hub II and a driven discI4. This vibration dampener is employed to dampen out any torsionalvibrations that may be set up in the crank shaft of the engine, and inview of the fact that it forms no part of the present invention, it willnot be further described. Facings I5 and I6 are secured to oppositesides of disk I4 near its periphery, and they may consist of anymaterial that has the required characteristics to give the correctfrictional gripping force, and at the same time has wearing qualitiesadapting it for this purpose. I prefer, however, to use the types ofmaterial which in practice have given very satisfactory results inautomatic slipping drive and clutch mechanisms of the Powerflo type.Frictional facings I5 and I6 may be secured to disk I4 in any suitablemanner, as for instance by rivets or the like, and they, along with diskI4, will be hereinafter referred to as the driven member. Facings may beannular discs, or they may be formed as segments and secured to disc I4in circularly spaced relation, in order to provide a flow of cooling aircurrents if desired. l

Facing I5, secured to disk I4, cooperates with the flat driving face offlywheel 4 and is adapted to be frictionally driven thereby. Facing I6,cooperates with a plate I1, which will be hereinafter termed theautomatic plate for the reason 75 that it is automatically actuated andis adapted to engage and clamp the driven member between it and the fiatface of the flywheel. Plate I1 is of substantial thickness so that itmay possess a sufilcient degree of rigidity to prevent undesirabledistortion and warpage thereof under the pressures and temperatures thatit is subjected to during operation of the mechanism.

A cover member I8 is secured to the flywheel by means of cap screws I9,and it is provided with embossed portions 2I in the regions of capscrews I9, for the purpose of spacing the cover from the flywheel for apurpose that will presently appear. Secured to the inner walls of coverI8, by means of a spot welding operation or the like, are threesymmetrically arranged lug or key members 23. Key members 23 arereceived in, and cooperate with the walls of' recesses 24 formed inautomatic plate I1 to establish a driving connection between flywheel 4and the automatic plate.

Disposed parallel to plate I1 is a plate 25, and

it will be hereinafter referred to as a. reaction plate, because ittakes the reaction of the speedresponsive mechanism in a manner to bepresently described. Reaction plate 25 is driven by automatic mate I1through the medium of a plurality of cap screws 21. Referringparticularly to Figure 3, 'each cap screw 21 is provided with a reducedend 28 that is threaded into automatic plate I1, and the thread employedis preferably of the Dordelet or other self-locking type so a's toprevent the cap screws from working loose in operation. Cap screws 21extend through, and lie in slidable driving engagement with the walls ofrecesses 29 formed in reaction plate 25, andare encircled by washers. 3|and compression springs 32. Springs 32 act against the heads of screws21 and react against plate 25, to thereby urgethe automatic and reactionplates toward each other at all times, and they will be hereinafterreferred to as holdback springs. The holdback spring assemblies arepreferably symmetrically disposed in pairs about the periphery of theplates and inthe present instance six are employed, but it is to beunderstood that more or less than six properly designed holdback springassemblies may be used if desired without in any way departing from thespirit of my invention. semblies accordingly establish a drivingconnection between the automatic and reaction plates,

and, at the same time, resiliently urge the latter toward each other. l

'Reaction plate 25-is normally urged toward the flywheel by a pluralityof compression springs 33, that are retained in position against plate25 by means of bosses 34 formed on the latter. Springs 33 react againstthe surface of cover I8, and are centered thereon by means of pressedout portions 35 formed in cover I8. Springs 33 are preferably six innumber and are disposed in substantially common radii with the holdbackassemblies. Reaction plate` 25, however, is normally held in theposition shown in Figure 1, when the driving shaft is operating at orbelow the idling speed of the engine or other prime mover, by means of athrowout mechanism that will presently be described.

Before proceeding to the description of the actuating mechanism fortheautomatic plate, it should be understood, that although I have illus-The holdback astrated the surfaces that engage facings I5 and I6 asplane in configuration, they may be grooved in the manner shown in mycopending application Serial No. 669,766 if desired.

of recesses 63 formed in plate 25, with the sides of 1 The automatic andreaction plates may be actuated away from each other by any suitablespeed-responsive mechanism, to produce clutch engagement, but in thepresent embodiment of my invention, it preferably takes the form. ofcentrfugally operable mechanism. Preferably three weight levers 5|,having integrally formed heads 52, are symmetrically arranged betweenthe pairs of pressure springs 33, and have their heads 52 received inrectangular recesses 53 formed in automatic plate |1.

Each lever 5| is provided with a pair olf threaded portions 54, whichare received in a pair of apertures 55 located'in a weightelement 56.

A reinforcing element 51 is disposed between each weight 56 and lever5|, and is provided with portions 5,8 that embrace the sides of lever5|, and a flat surface 59 that is adapted to abut the surface of Weight56. Weight 56 and member 51 are held in place on lever 5| by means ofnuts 6|, turned on portions 54, and seating in countersinks 62 formed inweight 56. When nuts 6| are turned home, the parts are rigidly clampedin assembled condition and portions 58 of member 51 cooperate with lever5| to prevent angular movement of the latter withrespect to weight 56.Although I prefer to secure levers 5| to weights 56 in the manner justdescribed, it is to be understood that the Weights may be integrallyformed with the levers if desired, without departing from the spirit ofmy invention.

Levers 5| are of substantial width and extend through recesses 63 formedin reaction plate 25. Heads 52 are provided with at faces 64 thatnormally abut the bottoms of recesses 53 when the driving shaft isoperating at, or below idling speed, and by the term idling speed,'Imean the particular desired automatic uncoupling or disengaging speed ofthe driven shaft, and if an internal combustion engine is employed asthe prime mover, the idling speed will lie in the neighborhood of fourhundred to ve hundred revolutions per minute.

Heads 52 are also provided with reaction faces 66 which abut the face ofreaction plate 25 at all times, and are designed for fulcrumingengagement therewith during operation of the weights. The surface ofplate 25 that cooperates with faces 66 of weight-heads 52 is preferablyground and polished so that relative sliding movement thereof may occurwith a minimum of friction.

Heads 52 have their outer sides relieved to provide knife-like edges 68which are adapted to rock or pivot in the dihedral angles defined by thebottom and outer faces of recesses 53 formed in automatic plate l1. Therelieving operation enables a good knife edge 68 to be formed on eachweight head, and allows pivotal movement thereof without interferencefrom the outer side walls i0 of recesses 53. However, it is to beunderstood that unrelieved weights may be employed in recesses that aresuitably designed so as to have relieved outer side walls, if desired.It is also to be understood that, instead of providing individualrecesses 5 53 for cooperation with the weight heads, a single annulargroove, as shown in my copending application, Serial No. 660,179, ledMarch 9, 1933, may be formed in automatic plate |1 if desired, withoutdeparting from the spirit of the present in- 0 vention.

Recesses 53 are formed in automatic plate I1 in any desired manner, asfor instance by a milling cutter or the like, and weight heads 52 areprevented from moving longitudinally Within the re- 5 casses so formed,by the engagement of the walls levers 5|. Heads 52 fit rather snuglybetween the inner and outer side walls of recesses 53 so that they arerestrained from shifting bodilyinwardly or outwardly, thereby insuringdynamic balance of the mechanism at all times. Knife edges 68 areadapted to cooperate with the vflat bottomr faces of recesses 53 andthereby act in linecontact upon plate |1 for a substantial distanceacross the face thereof, whereby uniform distribution of pressure over asubstantial area thereof is eifected. Each weight 56 is further providedwith recesses 69 which allow free operation thereof without interferencefrom bolts 21 and springs 33.

'The seats formed by the bottom and outer faces or walls of recesses 53constitute bearing recesses in which edges 68 of weight heads 52 areadapted to fulcrum, and although I prefer to employ this arrangement, itis to be understood that the relation of the parts may be reversed, andthe bearing recesses formed in weight heads 52, and the knife edgesformed on plate |1, or a member or members secured thereto, if desired,without departing from the spirit of the present invention.

The mass of weights 56, and the number of Weights and lever assembliesemployed in a particular installation, is determined by a considerationof the required pressure that they must transmit under the desired speedconditions to urge the clutch plates into final non-slipping engagement.In the automatic drive clutch mechanism shown, three equally spacedweight assemblies are preferably employed.

When shaft 3 is stationary, or is operating at, or below, a speedcorresponding substantiallyV to the idling speed of the prime moveremployed to drive it, the parts assume the positions in which they areshown in Figure 1. Heads 52 of levers 5| are clamped between plates |1and 25, under the inuence of springs 33 acting against plate 25 and capscrews 21, and plate, 25 is held in the position shown, against the`action of springs 32, by means of a throwout mechanism that will bedescribed hereinafter.

Extending through apertures 1| formed in plate 25, and preferablysymmetrically disposed between the weight assemblies, are a plurality ofbolts12. The heads of bolts 12 are provided with blade-like portions 13which seat in recesses 15 located in plate 25 and serve to hold bolts 12against rotation. Castle nuts 15 are threaded on bolts 1,2 and areadapted to be held in adjusted positions thereon by means of cotter pins16. Hardened Washers 11 are disposed on bolts 12 and cooperate withclutch ngers 18 to produce movement of plate 25 away from the flywheel.Fingers 18 are pivoted on roller or needle bearings 18' journaled onpins 19 secured in spaced ears 8| formed on bracket members 82. Pins 19are preferably held in position in ears 8| by means of cotter pins 83,and brackets 82 are secured against pressed in portions 84 by means ofrivets 85 or the like. Fingers 18 are provided with bifurcated portions86, and the latter have curved faces 81, that cooperate with washers 11in a manner to be presently described. Bolts 12 are also encircled bylight compression springs 88 and washers 89' and-the latter are urgedinto contact with levers 18 to hold the latter against rattling whenthey are not under the influence of springs 33.

Bolts 12 and nuts 15 are adapted to partially extend through apertures89 formed in cover I8,

and the apertures are preferably of a size sufficient to allow a wrenchor the like to be applied to nuts 15 for clutch adjustment purposes.

Levers 18 are provided with weight or mass portions 90, which functionto balance the levers and prevent them from responding to centrifugalforce and tend to impart declutching movements to theclutch parts.

Movement of the inner ends of fingers 18 to the left, in Figure l,through the intermediary of bolts 12, causes movement of plate 25 awayfrom the flywheel against the action of springs 33. Movement of thereaction plate produces similarmovement of plate |1 because the holdl5back assemblies hold the two plates in unitary relationship at alltimes. Fingers 10 are adapted 'to be actuated in this manner by means ofa throwout assembly that will now be described.

Cooperating with curved faces 93 formed on 20 fingers 18 is the flatface of a ball race 94, which cooperates with anti-friction balls 95disposed between race 94 and a cooperating ball race 96. Ball races 94and 96 are held in assembled relation with respect to each other bymeans of a.

combined retainer and reservoir defining member 91. Ball race 96 isrigidly mounted upon a sleeve 90 which is slidably mounted upon a hollowsupportingmember 99. 'I'he latter is preferably integrally formed withhousing I and is accurately machined to be disposed in axial alignmentwith the clutch mechanism and prime mover shaft 3 when the clutch isassembled, and is designed to provide a close sliding fit with sleeve98. Member 99 is preferably spaced substantially from, and isindependent of, shaft 9. Sleeve 98 is provided with a tapped bore |02into which a grease fitting |03 of well known construction is screwed.Bore |02 communicates with an axially extending passage |04 formed insleeve 98 so that lubricant introduced through bore |02 provideslubrication for axial movements of sleeve 98 and also provideslubrication for the bearing assembly through a passage |05 communicatingwith passage |04 and reservoir defining member 91 associated with thebearing assembly.

Sleeve 98 is prevented from rotating about support 99 by means of anapertured lug |06 formed on sleeve 9B. A stud |01 is slidably receivedin lug |06 and is threaded into an aperture in housing Formed onopposite sidesv of sleeve 98 are lugs |08 which cooperate with throwoutfingers |09 rigidly carried by a throwout shaft ||0. Shaft ||0 ispreferably journaled in, and

extends outwardly of clutch housing and carries on the end thereof aclutch pedal, (not shown) which is secured against rotation thereon.

Although I have disclosed a specific throwout assembly in connectionwith my invention, it

is to be understood that any suitable throwout mechanism normal to-theclutch axis for cooperating with the inner ends of fingers 18 may beemployed if desired, and a thoroughly practical mechanism obtained.

Before proceeding to further structure, it should be observed that thegreater length of driven shaft 9 is clear of supporting sleeve 99, thelatter being stationarily mounted in the clutch housing or casing.Therefore, substantial eccentric, or angular misalignment of drivingshaft 3 and driven shaft 9 can have no effect whatever upon thecooperation of the throwout bearing assembly and its cooperation withfingers 18. Moreover, since driving shaft 3, in the preshavinga facethat is substantially ent instance, is the crank shaft of the engine,and the bearing face of support 99 is carefully machined to lie exactlyparallel to driving shaft 3, their permanent alignment is assured andthe throwout bearing assembly, providing nuts 15 are properly adjusted,causes plate |1 to be disposed in proper angular relation at all times,regardless oi whether the clutch is engaged or disengaged. Moreover,fingers 18 will be held tight at all times, regardless of manufacturinginaccuracies, or inaccuracies that arise due to wear, by theirthree-point support on the face of the throwout bearing assembly whilethe throwout bearing is positively maintained in proper alignment byvirtue of the stationary guiding means formed on the clutch housing,prol viding smooth clutch action with minimum pedal operating pressuresat all times in a low cost construction requiring a minimum ofmanufacturing accuracy.

With reference to the automatic and reaction plates, it is observed thatthey are keyed together, or connected together for synchronous rotationby means of the holdback assemblies, and reaction plate 25 is in factcarried by automatic plate |1. Weights 56 are also carried by theautomatic plate, and as this weight and plate organization is ofcomparatively great mass, movement thereof radially or in any directionother than parallel to the axis of the mechanism, results in static aswell as dynamic unbalance thereof, and as a matter of fact it has beenfound in practice, `that for the clutch mechanism illustrated, a radial,or sidewise movement of four one-thousandths of an inch representsapproximately two inch-ounces tending to unbalance the mechanism.

In order for the plate and weight assembly to function properly, it mustbe capable of undergoing free axial movement. i By designing drivinglugs 23 and recesses 24 so as to provide sufficient play to permit thisaction, sufficient lost motion is usually introduced into the plateorganization to permit it to undergo a slight radial movement, and thisresults in the unbalanced condition just described. i

In order to eliminate this difficulty, the plate and weight organizationis so designed, that it is in substantial or complete static and dynamicbalance when the automatic plate is located on one side of themechanism, i. e., with the walls of recesses 24 in close contact withtwo of the driving lugs 23, and means are provided for maintaining theassembly in this condition dur-- ing all phases of operation of themechanism, with the result' that it is balanced at all times. Thespecific form of y means for producing this result may take any formdesired, but in the present embodiment of my invention, it consists 'ofa bowed leaf spring having an aperture ||2, which fits over and is heldin place by one o f the driving lugs 23. In view of the simple design ofthe present clutch mechanism, the parts thereof may be manufactured bylow-cost, quantity production methods, and yet provide plate and weightorganizations whose mass is fairly symmetrically distributed. However,if desired, masses, in the form of washers or the like may, if desired,lbe secured to parts of the mechanism for the purpose of balancing theweight and plate assembly when the latter is held in position againsttwo o f the driving lugs, and the appended claims are intended toembrace this method of balancing the mechanism. However I prefer tocompensate for imbalance of the part:

to the flywheel face by mechanism located externally of the clutch, inthe manner to be hereinafter described, so that it may be bal-ancedafter it has been assembled In view of the fact that spring III exerts africtional resistance against only one side of plate I 'I, engaging anddisengaging movements of the latter axially of the mechanism areyieldingly resisted or retarded to some extent, which may result in theautomatic plate tilting slightly as it undergoes movement into and outof engagement with facing I6. 'Ihis is an advantage rather than adisadvantage, however, because the slight tilting action which takesplace is not sufflcient to unbalance the mechanism, especially at thecomparatively low speed at which engagement occurs, and the resultinginitial partial and progressive engagement of automatic plate Il withfacing I6, as weights 56 rock outwardly,

imparts extremely smooth operating characteristics to the mechanism andgives a cushion disc" effect. When the clutch is fully engaged, theplates are not tilted, but are disposed parallel to each other andnormal to the axis of the mechanism, so that the mechanism does notvibrate, even at high speeds.

In the particular clutch mechanism illustrated, spring III preferablyexerts a force of approximately thirty pounds, and is designed to urgethe automatic plate toward the other lug assemblies and serves to takeup the play or lost motion therein. Spring III acts against and appliespressure to portions II3 of plate II, located either side of recesses24.

Spring III accordingly maintains the parts in balanced condition at alltimes, and yet, in view of its resilient nature, it does not interferewith free axial and slight tilting movements of automatic plate I l.Although I prefer to employ a spring of the type disclosed for holdingthe parts in balanced condition, it is to be understood that a tensionor compression spring, or any other suitable means, may be employed toproduce this result, without departing from the spirit of the presentinvention.

In order to provide dynamic and static balance of the mechanism as awhole, I provide balance assemblies which are preferably secured to theouter cylindrical portion of cover I8, and they are preferablysymmetrically located between the weight assemblies or radiallyoutwardly beyond levers 'I8, Each balance assembly preferably consistsof a pair of main or principal Weight members II5, which take the formof washers; and

a plurality of auxiliary weight members I I6 which consist of smallWashers in the present embodiment of the invention; which we held inplace by means of a bolt I II, passing through an aperture in cover I8,a nut H8 and a lock Washer H9.

The mass of the balance assemblies depends upon the nature of theparticular clutch mechanism and the dimensions and mass of the partsthereof. In the particular clutch illustrated, three symmetricallyarranged balance assemblies of the size shown are employed and theirmass is such as to offset the concentrated mass represented by theweight assemblies and render the mechanism both statically anddynamically balanced. In the event that after the balance assemblies areapplied to the mechanism, the latter 'is still out of either static ordynamic balance or both, because of unsymmetrical mass distributioncaused by manufacture of the Iparts by low-cost, quantity productionmethods, one or more washers IIS may be removed from, or added to ones'emblies as being secured to the cover, and pre' fer to utilize thistype of organization Abecause the mechanism can be balanced externallyof the mechanism after it has been completely assembled, it is to beunderstood, that if desired, the balance assemblies may be secured toreaction plate 25 over any other part of the mechanism without departingfrom the spirit of the present invention, and the appended claims areintended to embrace mechanisms of this character. It is also to beunderstood that the use of the balance mechanism just described, as Wellas the balance spring employed to yieldingly position the automaticplate, is not limited to the particular type of automatic clutchillustrated, and that they may, in fact, be employed for balancingmanually operable clutch mechanisms.

Clutch pedal shaft IIU is preferably adjustably held by a suitablemechanism in such a position that the throwout bearing assembly willhold the parts in the positions in which they are` shown in Figure 1when driving shaft 3 is stationary or is operating at, or below, apredetermined idling speed of the prime mover utilized therewith. Underthese conditions, a clearance exists between the plates and there isaccordingly no driving connection between shafts 3 and 9. Any suitablelatch mechanism may be associated with shaft IIO or the clutch pedal forholding shaft IIB in this position,- but I preferably Iemploy the typeof clutch'pedal latch mechanism disclosed in my copending application,Serial No. 660,179, filed March 9, 1933, and which may be referred tofor a full disclosure thereof. The throwout bearing assembly is shown inFigure 1 in what is termed its automatic position, and is so termedbecause it is preferably disposed in this position when the clutchmechanism functions, or is being employed as an automatic orspeed-responsive clutch.

The clutchpedal may-be depressed to move the throwout bearing assemblyto the left of the position shown in Figure 1, for manually declutchingthe mechanism in a manner to be hereinafter pointed out, and the partsof the latch mechanism are so designed to allow this movement of thepedal without interference.

The latch mechanism may be operated to allow the clutch pedal to retractand permit the throw- 4out bearing to move to the right of the positionAutomatic operation As driving shaft 3, and ywheel 4 are accelerated,vreights 56 gradually swing o'r rock outwardly about their knife-edges68 as axes in response to centrifugal force. As this occurs, reactionfaces 66 of heads 52 fulcrum and slide on the face of plate 25 and knifeedges 68, and by l engaging or working area,

virtue of their engagement and fulcruming action upon the fl'at bottomsurfaces of recesses 53 located in automatic plate I1, they forceautomatic plate I1 away from reaction plate 25 against 5 the actionoffholdback springs 32, and into engagement with facing I6 of disk I4,on a three-4 point support, thus causing disk I4 to move axially andbring the facing I5 thereof into contact,

Withthe/fiywheel face.

Movement ofautomatic plate I1 away from reaction member 25 is opposed byholdback springs 3 2, and therefore weights 56 are held under control.Holdback springs 32, herefore, in addition to predetermining the speedof the mechanism at which automatic engaging operation is initiated,exert a steadying influence upon the clutch parts.

After the driven member is thus frictionally clamped or gripped betweenautomatic plate I1 and flywheel 4, movement of plate I1 is substantiallyarrested, and further rocking movement of weights 56, in response toafurther .increase in centrifugal force, causes faces 65 of heads 52 toforce reaction plate away from the flywheel 25 against the action ofsprings 33. Movement of plate 25 in this manner causes pressure toslowly build up in springs 33, and a corresponding pressure is built upbetween the edges 88 of heads 52, and the bottoms of the recesses inautomatic plate I1.

It is observed that fulcrums 58 of weight heads 52 are disposedapproximately midway of the outer and inner peripheries of plate I1, andact in line contact therewith fora substantial distance across its face,applying substantially uniformly distributed pressures opposite thecenter of its Y thereby minimizing warping and distorting tendencies of4the plate under the pressures and temperatures to which it is subjectedduring operation.

The partial vacuum established by rotation of the parts causes an airstream to be drawn through the relatively large annularpassage be tweencover I8 and the throwout bearing and along the clutch axis. A part ofthe axial air stream passes over both faces of plate 25 between plates25 and l1, andv in this connection, it should be observed thatv platesI1 and 25v are substantially thermally isolated, and the air currentspassing between them effectively prevent the heat thatl is generated inplate I1, as the yresult of slipping, from being transmitted to plate25,' and possibly drawing or harmfully modifyingthe temper of springs 32and 33'associated with the latter. Another portion of the air streampasses outwardlybetween the plates and the heated, dust-laden air isexhausted from the mechanism through the space between the flywheel andcover I3. If desired, additional 50 openings may be formed in thecylindrical portion of cover I I for assisting in exhausting the heateddust-laden air from the mechanism, and fan blades or the like associatedtherewith-for drawing the air through the openings.

I'he Ventilating and dust-removing air may be introduced into, andexhausted from housing I in any desired manner, but I preferablycontemplate the use of thel organizations disclosed in applicationSerial No. 606,238, nled April 19,

I 70 1932, which 'have proved to be extremely efficient inpractice.

When-shaft 3 and flywheel 4 attain a predetermined speed, weights 56rock out into `contact witlrarcuately shaped stop faces I2I formed "'75on boss portions |22 of plate 25, as seen in and Figure 4. In order tostop weights 56 in a dennite plane that is normal to the mechanism, andthus insure dynamic balance of the device, preferably arcuately shapedstop-edges or faces |23 are accurately formed on weights 56. 'I'he stops5 are also designed to stop weights 55 with their centers of massequidistant from the axis of the mechanism. When the weights have .movedinto their outermost positions with their stop faces |23 in contact withstop faces I2I, the platesv are lO disposed innon-slipping engagementand further acceleration of shaft 3 is ineffective to cause a furtherpressure to be built up between the plates. 'I'he plates are therebyheid in nonslipping engagement under a predetermined 15 pressure, and apositive friction coupling exists between shafts 3 and 3.

Stop faces |23 are so located on weights 56, that no matter how greatthe magnitude ofthe centrifugal force set up in lweights 56 may be, 20it is incapable of causing the mechanism to exhibit declutchingtendencies at high speeds.

With reference to levers 1li, they are designed so that, when the clutchis engaged, the masses thereof are so located with respect to their.piv- 25 ots, that the centrifugal forces set up therein, as the resultof rotation of the mechanism, do not exert substantial rotativeinfluences in the levers. When the parts are disposed in auto maticidling position (Figure 1) the. greater por-l #0 .tion vof the masses oflevers 18, is located to the right of their pivots, but this is not adisadvantage, however, because the parts only assume these positionswhen the mechanism is rotating at low speeds, and the centrifugalforfces existing 35 under these conditions are likewise of low magenitude. l

When the clutch has been automatically engaged in the manner justdescribed, the inner ends of levers 18 move away from the throwout. 40assembly, and the inner ends of the levers are spaced a substantialdistance from the latter.v This is brought about through movement of reaction plate 25 to the right, and the levers are held in this positionunder 'the influence lof. 45

in response to centrifugal force, exhibited tendencies to rotate so asto move their inner ends 55 to the-left,- the levers would transmitdeclutching lforces to the reaction plate. However, if the leversshould. be designed so that they tended to rotate and bring their innerends toward the throwout assembly in response to centrifugal w forcesset up therein, such movement would b'e ineilective to modify the platepressure estab-A lished by the action of weights 56, because faces 81 oflevers 18 would merely move away from washers 11, against the action ofsprings lSii. 65 Therefore, the prime requisite is that the levers,

in response to centrifugal force, will not exhibit tendencies to move insuch manner as to bring their inner ends away from the throwout assemblywhen the clutch mechanism is automatically engaged.

In view of the resilient nature of the backing means for the reactionmember, should certain weights 56 swing further outwardly than theremaining weights, during the engaging opera- 7b tion, the pressureexertedgby them is nevertheless uniformly distributed between thesegments of plate Il for the reason that reaction plate 25 can tilt orfloat, and take a slight angular position with respect to automaticplate Il, due to the fact that the sole movement limiting means of thereaction member is constituted by bolts 21, and the latter are designedto provide sufcient play or clearance to permit this tilting action.

When the automatic engaging operation, just described, is taking place.,reaction plate 25, and its associated parts, are roved to the right ofthe positions in which they are shown in Figure l. Movement of reactionplate 25 to the right allows springs V8B to move the inner ends oflingers 18 away from their cooperating engagement with the face of thebearing assembly, thereby relieving` the throwout bearing assembly ofpressure. The throwout bearing assembly therefore only operates when theclutch is operating at idling speeds or is manually declutched, and ittherefore receives only a minimum amount of wear and its life istherefore greatly increased.

With the above described mechanism installed in a motor vehicle providedwith a conventional three-speed transmission, and the vehicle is on aYsubstantially level surface, the transmission may be placed in highgear without operating the clutch pedal if the engine is operating belowthe engaging speed of the clutch mechanism, and the engine may beaccelerated to produce automatic clutch engageme'nt in the mannerpreviously described. During the engaging operation, a

r slipp-ing drive exists between shafts 3 and 9 and the vehicle isaccelerated smoothly and without shock and in view of thespeed-responsive en-4 gaging characteristics of the .mechanism, it isimpossible to stall the engine through improper actuation of theaccelerator.` When the engine and vehicle speeds are properlycorrelated, the clutch plates are brought into full driving engagement,thereby automatically establishinga direct coupling between shafts 3 and9.

When operating in this manner, and it is desired to decelerate or stopthe vehicle, the accclerator is released and the brakes are applied.

When the vehicle has decelerated to a speed corresponding substantiallyto engine idling speed, through the combined braking'action of theengine and the vehicle brake mechanism, weights 56 rock inwardly underthe influence of holdback springs 32 and disengagement of the clutchplates is automatically effected. Shafts 3 and 9 are therebyautomatically uncoupled and the braking action of the engine is nolonger transmitted to shaft 9, but in View of the fact that thedisengaging speed of the.A clutch mechanism is usually fairly low, thevehicle isdecelerated to a relatively low speed under the brakinginfluence of the engine before the mechanism automatically disconnectsshafts 3 and 9. n

The vehicle may be brought to a complete stop by continued applicationof the brakes, or', if traic conditions permit, the accelerator may bedepressed and the engine accelerated to produce almost immediatere-engagement of the mechanism and the vehicle again picked up in highgear.

Due to its slipping drive characteristics, the present mechanism'constitutes a drive mechanism as well as aclutch, and while it does notmultiply the torque delivered from shaft 3 to shaft 9, it permits theengine to operate at a higher speed, and, consequently, at a higherpoint on its speed-torque curve, and deliver more power, than ifsubstantially non-slipping conditions existed between shafts 3 and 9,and thisy When the facings have become thin, as the result of particlesthereof wearing away during operation, and cause the idle release plateclearance to become too great, the throwout bearing assembly is movedslightly to the right of the position in which it is shown in Figure 1,by adjusting the latch pedal on its shaft, or adjusting the latchmechanism in any suitable manner, in order to dispose automatic plate l1closer to the flywheel and establish proper plate clearance for idlerelease conditions. In copending application, Serial No. 595,184, filedFebruary 25, 1932, adjusting mechanisms are -disclosedI that have provedto be highly successful in practice, and I contemplate using theseadjusting lmechanisms in the present invention. When facing wear hasbeen compensated for several times, by periodically adjusting thethrowout bearing assembly further to the right, ngers or levers 'I8 maybe allowed to move to the right to such an extent that, under someconditions they take undesirable angular positions. This condition isreadily remedied, or compensated for', by adjusting nuts l5 an equalamount, and sufiicient to bring levers 18 into the proper positionsdesired. The external adjusting mechanism previously referred to maythen be manipulated to establish proper idle release clearance betweenthe plates, and clearance gauges may be introduced between the cover andthe flywheel and inserted between facing l and the Aflywheel face toascertain if the plate clearance is correct. The normal plate wearcompensating adjustment, however, is made externally of the clutchhousing by adjusting the angular position of shaft I I0 into properautomatic position, and therefore this adjustment does not in any wayaffect the adjusted positions of nuts 15, and consequently, the angularrelation of the plates.

Manual disengagz'ng operation When the plates have beenv automaticallybrought into full driving engagement in the manner previously described,the clutch pedal may be depressed to displace the throwout bearingassembly andthe inner ends of leversr'l to the left of the positions inwhich they are shown in Figure 1. Movement of levers 'I8 in this mannercauses them to fulcrum about and react against therefore, thedeclutching operation does not involve retracting the weights againstthe action of centrifugal force, which, at high speeds might besufficiently high to preclude aleting the manual declutchlng operation.

In traffic, when it is desired to get the vehiclev Manual engagingoperation As has been previously pointed out, when shaft 3 is operatingsubstantially at the idling speed of the prime mover,or is stationary,and the clutch pedal is latched to dispose the throwout bearing n` theautomatic position shown in Figure 1. a clearance exists between theclutch plates, and shafts 3 and 9 are accordingly disconnected. When itis desired to establish a driving'connection between shafts 3 and 9,under these conditions, .the latch associated with the clutch pedal isactuated to allow the latter to move into its retracted position.Retraction of the clutch edal allows the throwout bearing assembly tomove to the right under the influence of, springs 33, and the latter,acting against the reaction plate, bring reaction plate 25 and automaticplate I1 to the left of the positions in which they are shown in Figure1, with automatic plate I1 in driving engagement with the driven member,thereby coupling shafts 3 and 9. With the aboveA described mechanisminstalled in a motor vehicle, it is frequently desirable to effect thismanual engaging operation. For instance, when the motor is cold and thebattery is low, it is desirable to place the transmission in gear andpush or coast the vehicle to turn the engine over. Also when stopping ona steep grade, positive engagement of the clutch, with the transmissionplaced in low or reverse gear, provides an emergency brake that cannotbe inadvertently released; or if the motor stalls,

from lack of fuel or any other cause, the vehicle can pull out ofdangerous positions by propelling it in low gear with the startingmotor.

The present clutch mechanism is designed to be fully engaged when shaft3 attains a speed of approximately one thousand revolutions per minute,and as the weights rock out into firm contact with their ,stops at thistime, the only ,speed at which themechanism may possibly becomeAunbalanced is below one thousand revolutions per minute (as forinstance by the weights moving outwardly unequally), but atthis'comparatively low speed, such unbaiance, if it does exist, does notresult yin harmful vibration of the 50 mechanism. Above one thousandrevolutions per minute, where unbalance in the mechanism would possiblyresult in harmful vibration, it is maintained in accurate staticl anddynamic balance by means of the balancing mechanisms, and 66 anextremely practical and effective mechanism is thereby produced. v

Although I have disclosed, and prefer to employ clutch mechanisms of.the single plate type, i. e., clutch mechanisms having two driv- 70 ingmembers and a single driven member, it is to -be distinctly understoodthat my invention contemplates clutch mechanisms wherein three or moredriving members cooperate with two'or more driven members to effect adriving connec- 75 tion between the driving and driven shafts, and

ing member;

the appended claims are intended to embrace clutch mechanisms of thischaracter.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent iszl. In a clutch mechanism, a clutch element;

lmeans mounting said element for movement into and out of acentrifugally balanced position; and means for yieldingly maintainingsaid element in said centrifugally balanced position.

2. The mechanism described in claim 1, to-

gether with balancing means associated with,

and adapted to balance said mechanism, said balancing means being alsoadapted to exert balancing influences upon said element.

3. In a clutch mechanism, a driving member; a driving plate; means forcausing said driving member to drive said driving plate and permittingthe latter to move axially of the mechanism for clutching anddeclutching purposes, said means also permitting said driving plate toundergo relatively slight radial movements; and

resilient means for yieldingly restraining said driving plate againstradial movement.

4. In an automatic clutch mechanism, a drivan automatic plate; means forcausing said driving member to drive said automatic plate and permittingthe latter to undergo movement 'axially of the mechanism for clutchingand declutching purposes, said means also permitting said automaticplate to undergo relatively slight radial movements; and resilient.means for yieldingly restraining said driving plate against radialmovement.

5. The automatic clutch mechanism described in claim 4, whereinspeed-responsive means are carried by said automatic plate, and whereinsaid resilient means is operative to centrifugally balance the latter.

6. In a clutch mechanism of the type wherein a driving plate is mountedfor axial movement. and is capable of slight radial movements, the

method of establishing and maintaining the mechanism in balance at alltimes, which comprises, distributing the weight or mass of the plate'sothat it is balanced when disposed in one of its'extreme radialpositions, and re'silientlyl urging the plate toward'said one extreme.radial position with a force sufliciently great to yieldingly maintainthe plate in its balanced position at all times during normal operationof the clutch mechanism.

7. In an automatic clutch mechanism, rotatable driving and drivenvmembers mounted for engagement and disengagement; speed responsivemeans i'or forcing said members into frictional engagement; a pluralityof levers for controlling engagement and ldisengagement of said membersand mounted for rocking movement in planes disposed substantiallyradially with respect to -the axis of rotation of said driving anddriven members, said levers being automatically rockable into angularpositions when said mem- 8. In a clutch mechanism, a supporting struc--turc mounted for rotation; a irictional driving plate; means forestablishing va driving connection between said supporting structure andsaid driving plate, comprising at least three lug elements connected tosaid supporting structure and engaging driving faces provided on saiddriv.-

ing plate, said means permitting said driving plate to move axially ofthe mechanism for clutching and declutching purposes and also permittingsaid driving plate to undergo relatively slight radial movements; and atleast one spring means acting upon said driving plate and yieldablyrestraining the latter against radial movement.

9. The clutch mechanism described in claim 8,

wherein said means comprises a single spring located adjacent one ofsaid lugs and bearing against the periphery vof said driving plate.4

10. In a clutch mechanism, a clutch element; means mounting said elementfor movement into and out of a dynamically balanced position; and meansfor yieldingly maintaining said element in said dynamically balancedposition.

11. In a'clutch mechanism, a driving member, a driving plate; means forcausing said driving member to drive said driving plate and permittingthe latter to move axially of the mechanism for clutching anddeclutching purposes, said means also permitting said driving plate toundergo relatively slight radial movements into and out of a dynamicallybalanced position, and resilient'means for yieldingly restraining saiddriving plate against radial movement out of said dynamically balancedposition.

12. In an automatic clutch mechanism, 'a driving member; an automaticplate; means for causing said driving member to drive said automaticplate and permitting the latter to undergo movement axially of themechanism for clutching and declutching purposes, said means alsopermitting said automatic plate to undergo rela- 1'4. In a clutchmechanism oi the type where- 'A in a driving\plate is mounted for axialmovef ment, and is capable of slight radial movements, the method ofestablishing and maintaining the mechanism in dynamic balance at alltimes, which comprises, distributing the weight or mass of the plate sothat it is balanced when disposed in one of its extreme radialpositions,

and providing the mechanism with means i'orv yieldingly maintaining theplate in its balanced position.

JOSEPH E. PADGETI.

